1. Mix yeast with 1?2 cup warm water in a small bowl, and set aside until yeast dissolves and little bubbles begin to appear on the surface, about 10 minutes.
Meanwhile, heat rice flour in a wok or large skillet over medium heat, stirring constantly, until flour is hot to the touch and turns from bright white to a creamy off-white, about 5 minutes. Do not brown. Remove wok from heat, and set aside to cool.
Combine farina and 1 cup water in a small saucepan, and bring to a boil over medium-high heat. Reduce heat to low, and cook, stirring constantly, until thickened, 2–3 minutes. Remove pan from heat, and stir until cool.
Put cooled rice flour, coconut. 4 tsp sugar, cooled farina, and proofed yeast in a large bowl, and whisk in enough water (about 1 1?2 cups) to make a thick batter. Cover with plastic wrap, and set aside in a warm, moist place (in a turned-off oven alongside a bowl of hot water, if you like) until batter expands slightly and becomes bubbly, 5–8 hours. (Batter may be refrigerated for several hours; return batter to room temperature before frying.) Whisk coconut milk, salt, and remaining 1 1?2 tsp. sugar into fermented batter. It should be the consistency of foamy cake batter; thin the batter with a little water, if needed.
Preheat oven to 200°. Heat a nonstick griddle or large skillet over medium heat. For each pancake, ladle about 1?4 cup of batter onto the hot griddle, and cook until the underside has browned to the color of cinnamon, about 3 minutes. Flip pancake over with a spatula, and brown other side, about 2 minutes more. Pancake should be about 1?2" thick and laced with fine holes. Transfer to a platter, cover with a clean kitchen towel, and keep warm in oven. Repeat with remaining batter.